This invention relates to a fuel-injection device for use in an internal combustion engine preferably for use in an automotive vehicle. The device includes an injection pump whose plunger is displaceably mounted in a bore of a guide body, and a nozzle element directly pressed against the front face of the guide body. The nozzle element includes a valve needle which controls the spray hole of the nozzle element. The valve needle projects into a bore beginning on the front face of the guide body and extends to a receiving space provided in the guide body. In the receiving space a spring element is arranged to press the valve needle on its valve seat, wherein laterally beside this receiving space for the spring element a fuel channel is arranged in the guide body. The fuel channel opens into the front face of the guide body and connects the working chamber of the injection pump with the nozzle element.
A fuel-injection device of this kind is known from the German specification OS No. 1,805,024. This device differs from other known designs substantially in that there is only one high-pressure sealing surface between the guide body and the nozzle element.
In this known embodiment the receiving space for the spring element is formed as a pocket hole centrally from the front face of the guide body. Thus the diameter of the bore on the front face of the guide body is at least as large as the diameter of the spring element which has to be accommodated in this receiving space. Because the spring diameter depends on the desired opening pressure of the valve and because a certain wall thickness is necessary between the bore leading to the receiving space and the fuel channel to provide stability, the known embodiment has a relatively large diameter on the front face of the guide body and thus the diameter of the nozzle element is relatively large. A fuel-injection device of this kind with a relatively large space requirement can be used without difficulty for motors of a larger size as used in the ship industry, however the utilization for a motor vehicle engine raises problems. Moreover the extent of the density at the front face of the guide body depends on the size of this front face, so that a smalller design is preferred.